Modular final drive for a track-type vehicle

ABSTRACT

A modular final drive for a track-type vehicle includes a housing containing a speed reduction gear train which drives a track engaging sprocket. The housing is detachably mounted solely on the rearward end of a track roller frame to facilitate expeditious assembly and servicing.

United States Patent 1 Bowen et al.

[ Nov. 20, 1973 [22] Filed:

[ MODULAR FINAL DRIVE FOR A TRACK-TYPE VEHICLE [75] Inventors: Harry H.Bowen, Pekin; Lawrence F. Clancy, Peoria; Stanley A. Jorgensen, Oswego,all of I11.

[73] Assignee: Caterpillar Tractor Co., Peoria, 111.

Apr. 3, 1972 [21] Appl. No.: 240,734

[52] U.S. Cl. 180/6.48, 180/6.58, ISO/9.62, 305/28 [51] Int. Cl B62d11/04 [58] Field of Search 180/6.48, 6.58, 6.7, 180/9.2 R, 9.62, 9.64;305/28 [56] References Cited UNITED STATES PATENTS 3,480,097 11/1969Solokhin et al ISO/6.48 1,879,218 9/1932 Hanson 180/6.58

3,416,623 12/1968 Boone ISO/6.48

FOREIGN PATENTS OR APPLICATIONS 604,334 7/1948 Great Britain 180/9.62

Primary Examiner-Benjamin Hersh Assistant Examiner-Leslie J. PapemerAttorney--Paul S. Lempio et al.

[57 ABSTRACT A modular final drive for a track-type vehicle includes ahousing containing a speed reduction gear train which drives a trackengaging sprocket. The housing is detachably mounted solely on therearward end of a track roller frame to facilitate expeditious assemblyand servicing.

8 Claims, 4 Drawing Figures WAWAWAWAWAWL MODULAR FINAL DRIVE FOR ATRACK-TYPE VEHICLE BACKGROUND OF THE INVENTION Conventional track-typevehicles oftentimes employ a pair of final drive gear cases which areindividually attached to a large central housing, commonly known as abevel gear case. Consequently, servicing of the final drive gear trainusually requires the disassembly of a plurality of individual housingcomponents. Servicing thus becomes tedious, onerous and time-consumingand is most conveniently accomplished in a repair.

shop, which results in excessive down-time, particularly when thevehicle is transported an appreciable distance from the job site to theshop.

Occasionally field servicing is necessitated which gives rise to seriousproblems due to the inaccessibility of the final drive unit, locatedbeneath the vehicle, and by adverse weather conditions which arefrequently encountered. Furthermore, when a new part is needed themachine often remains idle for a considerable period of time. Access tothe final drive unit and attendant components is further complicated bythe location of the operator station, fuel tank, hydraulic componentsand other structures which are normally situated immediately above thefinal drive housing.

A track-type hydraulic excavator normally has its final drive housingwelded or otherwise integrally formed with its associated track rollerframe. Since the undercarriage directly supports the excavatorssuperstructure, containing the operator station, engine and earthworkingequipment,. the inner portion of the final drive housing must beseparated to service the internal components, thus exposing them to dirtand possible damage. Accordingly, in view of the relatively inaccessiblelocation of such housing, the same problems as discussed above aresimilarly experienced with these types of vehicles.

SUMMARY AND OBJECTS OF THE INVENTION Accordingly, an object of thisinvention is to provide a modular final drive for a track-type vehicleadapted for convenient removal as a unit from a track roller frame forindependent servicing.

Another object of this invention is to provide a modular final drivewhich can be serviced or replaced as a unit without exposing internalcomponents thereof to a dirt-laden environment and damage and withouthaving to remove attendant major components of the vehicle.

Another object of this invention is to provide a modular final drivewhich carries a track roller thereon to position such track roller inclose proximity to.a track drive sprocket.

Other objects and advantages of this invention will become apparent withreference to the accompanying drawings and following description.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a partial, side elevationalview of a hydraulic excavator having a modular final track drive of thisinvention removably mounted therein.

FIG. 2 is an enlarged, top plan view of the track drive and attendantsupport structures, taken in the direction of arrows II-II in FIG. 1,with a top portion of an endless track assembly removedtherefrom forclarification purposes.

FIG. 3 is a side elevational view of the track drive.

FIG. 4 is a bottom plan view of the track drive, taken in the directionof arrows IV-IV in FIG. 3, with the track assembly removed forclarification purposes.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. 1, a hydraulicexcavator 10, disposed for movement along a longitudinal axis thereof,comprises a mobile undercarriage 11 having an upper unit 12 rotatablymounted thereon. The upper unit comprises a power plant 13, an operatorsstation 14 and an implement mounting boom 15. The undercarriagecomprises a pair of laterally spaced and parallel endless trackassemblies 16 (one shown) suitably mounted on a track frame 17 by anidler 18, track rol- Iers 19, track support rollers 20 and a bull wheelor drive sprocket 21 of the final drive means or track drive 22 of thisinvention. The herein described track drive and associated trackassembly is duplicated on the opposite side of the excavator. Althoughsuch track drive is herein described in association with the illustratedhydraulic excavator, it should be understood that such track drive hasapplication to other types of track-type vehicles.

As shown in FIGS. 2 and 3, the final track drive comprises a hydrostaticdrive motor 23 arranged to drive sprocket 21 through a speed reductiongear train, illustrated by broken lines in FIG. 3. The gear train maycomprise a pair of intermeshed cluster gears 24 and 25 drivinglyinterconnected between an input gear 26 and an output gear 27. The inputgear is connected to the output shaft (not shown) of motor 23 through anormally engaged disc-type parking brake 28 whereas the output gear isdrivingly connected to the sprocket.

The final drive further comprises a housing 29, having motor 23 andbrake 28 mounted thereon, and which encloses and supports the reductiongear train. The housing comprises an inwardly disposed cover 30 and aplurality of bearing cages 31, 32 and 33 attached thereon whichcooperate with cover 30 to respectively mount gears 24, 25 and 27therebetween. The housing has an outwardly extending, tapered armportion 34 having a broad mounting face 35 formed on the front sidethereof. The housing is detachably mounted at forwardly disposedmounting face 35 to a flush, rearwardly disposed mounting-flange 36 oftrack frame 17 by a'plurality of fastening means, such as bolts 37.

The arm portion is contoured to define an arcuate cavity 38 (FIG. 3) forsubstantially accommodating a rearwardmost track roller 19' thereinwhich is in substantial linear alignment with track rollers 19 (FIG. 1).As shown in FIG. 4, such track roller is attached beneathhousing 29 by apair of laterally spaced end caps 39, secured by bolts 40 to planarsurfaces 41 and 42, formed -on lower surface portions of arm 34. Thedisposition of arcuate cavity 38 with respect to theouter periphery oftrack roller 19 facilitates the location of sprocket 20 in closeproximity to track frame 17.

Fieldservicing of final track drive 22 is accomplished by first removingtrack assembly 16 in a conventional manner. The modular final trackdrive, including housing 29, the reduction gear train, sprocket 21 andrearmost track roller 19', can then be removed as a unit from trackframe 17 by solely removing bolts 37. The co-extensive contactingsurface areas at the mounting means comprisingmounting face 35 andflange 36 are sufficiently large to fully mask the rearward end of thetrack frame to fully secure the track drive to the track frame in acantilevered manner while yet affording a high degree of structuralintegrity thereat.

Thus, the compactness of the final track drive facilitates itsexpeditious detachment and handling in the field in contrast toconventional final drives which are normally welded to a supportingtrack frame. Furthermore, housing 29 completely encloses the internaldrive components thereof so that they are not exposed to dirt orpossible damage when the final drive is so removed. Assembiy lineproduction methods are also facilitated since the final track drive canbe tested prior to its installation on a vehicle.

While the invention has been described and shown with particularreference to the preferred embodiment, it will be apparent thatvariations might be possible that would fall within the scope of thepresent invention which is not intended to be limited, except as definedin the following claims.

What is claimed is:

l. A modular final drive in combination with a tracktype vehicle havinga track roller frame, said final drive comprising a housing,

a gear train disposed within said housing,

a track driving sprocket mounted on the housing and drivingly connectedto said gear train,

mounting means for detachably securing said housing to said track rollerframe so that said housing, said gear train, and said sprocket can beremoved as a unit from said track roller frame to allow independentservicing thereof and a track roller rotatably mounted on said housingin close proximity to said sprocket.

2. The invention of claim 1 wherein said mounting means comprises aforwardly disposed mounting face on said housing, a rearwardly disposedmounting flange secured on said track roller frame and fastening means,solely mounting said housing on said frame, removably attaching saidmounting face in flush relationship on said mounting flange.

3. The invention of claim I wherein said housing includes an armextending laterally across said sprocket and having means forming anarcuate cavity therein disposed in close proximity to said sprocket andwherein said track roller is mounted on said arm and is substantiallydisposed within said cavity.

4. The invention of claim 3 further comprising a plurality of additionaltrack rollers mounted on said track roller frame in substantial linearalignment with the track roller mounted on said housing and a motormounted on said housing and operatively connected to said gear train forselectively driving same.

5. In an undercarriage for a track-type vehicle com prising a trackroller frame having a rearwardly-disposed mounting flange thereon,

a modular final drive means enclosed in a housing having an outwardlyextending arm and a forwardly-disposed mounting face formed on said arm,said mounting face and mounting flange being at least substantiallyco-extensive with respect to each other,

fastening means for removably securing said housing on said track rollerframe by maintaining said mounting face and said mounting flange inclose intimate contact with each other so that said modular final drivemeans can be selectively removed as a unit from said track roller frame,and

a track roller rotatably mounted on said housing in close proximity tosaid sprocket.

6. The invention of claim 5 wherein said drive means comprises a trackdriving sprocket rotatably mounted on said housing and wherein said armhas means defining an arcuate cavity therein disposed in close proximityto said sprocket, said track roller substantially disposed within saidcavity.

7. A track-type vehicle disposed for movement along a longitudinal axisthereof comprising a pair of laterally spaced and parallel trackassemblies extending in the direction of said axis,

a frame supporting each of said track assemblies, and

modular final drive means for selectively driving each one of said trackassemblies, said final drive means comprising a housing detachablymounted on a rearward end of a respective one of said frames by mountingmeans, said mounting means comprising a forwardly disposed mounting faceon said housing, a rearwardly disposed mounting flange secured on saidframe and fastening means, solely mounting said housing on said frame,removably attaching said mounting face in flush relationship on saidmounting flange,

motor means mounted said housing, rearwardly of said frame,

a speed reduction gear train entirely mounted in said housing andoperatively connected to said motor means to be driven thereby, and

a drive sprocket mounted on said housing and operatively connected tosaid gear train and to a respective one of said tracks.

8. The invention of claim 7 wherein said track-type vehicle constitutesan excavator having an upper unit rotatably mounted on an undercarriagecomprising said track assemblies and said frame.

1. A modular final drive in combination with a track-type vehicle havinga track roller frame, said final drive comprising a housing, a geartrain disposed within said housing, a track driving sprocket mounted onthe housing and drivingly connected to said gear train, mounting meansfor detachably securing said housing to said track roller frame so thatsaid housing, said gear train, and said sprocket can be removed as aunit from said track roller frame to allow independent servicing thereofand a track roller rotatably mounted on said housing in close proximityto said sprocket.
 2. The invention of claim 1 wherein said mountingmeans comprises a forwardly disposed mounting face on said housing, arearwardly disposed mounting flange secured on said track roller frameand fastening means, solely mounting said housing on said frame,removably attaching said mounting face in flush relationship on saidmounting flange.
 3. The invention of claim 1 wherein said housingincludes an arm extending laterally across said sprocket and havingmeans forming an arcuate cavity therein disposed in close proximity tosaid sprocket and wherein said track roller is mounted on said arm andis substantially disposed within said cavity.
 4. The invention of claim3 further comprising a plurality of additional track rollers mounted onsaid track roller frame in substantial linear alignment with the trackroller mounted on said housing and a motor mounted on said housing andoperatively connected to said gear train for selectively driving same.5. In an undercarriage for a track-type vehicle comprising a trackroller frame having a rearwardly-disposed mounting flange thereon, amodular final drive means enclosed in a housing having an outwardlyextending arm and a forwardly-disposed mounting face formed on said arm,said mounting face and mounting flange being at least substantiallyco-extensive with respect to each other, fastening means for removablysecuring said housing on said track roller frame by maintaining saidmounting face and said mounting flange in close intimate contact witheach other so that said modular final drive means can be selectivelyremoved as a unit from said track roller frame, and a track rollerrotatably mounted on said housing in close proximity to said sprocket.6. The invention of claim 5 wherein said drive means comprises a trackdriving sprocket rotatably mounted on said housing and wherein said armhas means defining an arcuate cavity therein disposed in close proximityto said sprocket, said track roller substantially disposed within saidcavity.
 7. A track-type vehicle disposed for movement along alongitudinal axis thereof comprising a pair of laterally spaced andparallel track assemblies extending in the direction of said axis, aframe supporting each of said track assemblies, and modular final drivemeans for selectively driving each one of said track assemblies, saidfinal drive means comprising a housing detachably mounted on a rearwardend of a respective one of said frames by mounting means, said mountingmeans comprising a forwardly disposed mounting face on said housing, arearwardly disposed mounting flange secured on said frame and fasteningmeans, solely mounting saId housing on said frame, removably attachingsaid mounting face in flush relationship on said mounting flange, motormeans mounted said housing, rearwardly of said frame, a speed reductiongear train entirely mounted in said housing and operatively connected tosaid motor means to be driven thereby, and a drive sprocket mounted onsaid housing and operatively connected to said gear train and to arespective one of said tracks.
 8. The invention of claim 7 wherein saidtrack-type vehicle constitutes an excavator having an upper unitrotatably mounted on an undercarriage comprising said track assembliesand said frame.